1. Field of the Invention
The present invention relates to a gas lighter ignitable upon depression of a pressing means. More particularly, the present invention relates to a gas lighter with a safety device which ordinarily remains unignitable, that is, in an ignition locked state by the engagement of a resilient leaf on a lighter main body or the pressing means with the lighter main body or the pressing means but becomes ignitable by releasing the ignition lock, that is, rendering the resilient leaf deformed when the lighter is in use.
2. Description of the Prior Art
A gas lighter is a convenient tool which can be easily ignited by the depression of a pressing means such as an actuation lever or the like, but which may be considered not suitable for those who, like children, are unfamiliar with the proper use of the lighter in view of safety, because it is possible for them to ignite the lighter inadvertently. Also, the lighter may be ignited by unintentional depression of the pressing means upon coming into accidental contact with another object.
For these reasons, there is a demand for a gas lighter having an improved safety which prevents the inadvertent ignition of a lighter by those who are unfamiliar with the proper use of that lighter, and prevents the occurrence of unintentional ignition. In response to this demand, child resistant gas lighters with various types of safety device have been heretofore put forward. Most of the safety devices built into these child resistant gas lighters have a lock mechanism which prevents depression of the actuation lever and allows the depression of the actuation lever when it is released. However any of the conventional child resistant gas lighters will have drawbacks in their usage, and hence it is desirable for the gas lighter to be improved for practical use.
For instance, as disclosed in U.S. Pat. Nos. 4,859,172, 4,786,248, and 4,784,602 and Japanese Utility Model Publication No. 3(1991)-35971, any one of the disclosed safety devices is provided with a lock member for preventing depression of the actuation lever. Since the lock member is manually movable between a lock position and a release position, the lock member tends to stay at the release position without a manual recovery from the release position to the initial position after the use of the lighter, whereby the safety device remains unlocked. Leaving the lock member at the release position permits the depression of the actuation lever, which renders the safety device inoperable. Specifically then, to ensure safety, the existing safety devices always require a manual re-locking operation after the use of the lighter with the lock mechanism unlocked, and hence there were expected further improvements of the lock mechanism in terms of safety.
To solve the drawbacks set forth above, there have been put forward, as a safety device having a lock member to hinder the depression of the actuation lever, safety devices with what is called an auto-return function wherein the lock member automatically returns to the lock position in response to the ignition operation after the lock member has been manually moved to the release position. U.S. Pat. Nos. 5,002,482, and 3,898,031 and Japanese Unexamined Patent Publication No. 3(1991)-25215, for instance, disclose such safety devices as having the auto-return function which allows automatic return of the lock member to the lock position in response to the ignition operation. With these safety devices, however, the lock mechanism is only released by motion of a finger along an L-shaped path. This makes the lock mechanism inferior in operability and in the ease of releasing the lock member because a lighter of this type generally requires operation with a single finger, such as a thumb, leading to different results depending on the users. Therefore, safety devices of this type can be said to be disadvantageous in practical use. Further, the operation of these safety devices is unreliable because of a probability that the lock member will return to the lock position by its own reactive force caused by the resilience of the material constituting the lock member.
Furthermore, there have been proposed safety devices wherein the lock member is released by the motion of a finger not along the L-shaped path but along a simple linear path. However, any of those have drawbacks in practical use. The safety device as disclosed in, for example, Japanese Patent Publication of Translated Version (PCT) No.3(1991)-501647 is provided with an automatic return function wherein the part of a lock member composed of a spring is moved along an arcuate path to a release position and held there, then it automatically returns to a lock position in response to ignition operation. In this type of safety device, the arrangement for guiding the release of the spring-like lock member is not satisfactory, and accordingly the lock member cannot be steadily released. This adversely affects the ease of releasing the lock mechanism in the gas lighter, which is generally operated with a single finger, and, as with the preceding example, resulting operations will be different depending on the users. Since the lock member itself is made of a spring, the lock member may become deformed and cause failure of the lock mechanism after repeated use of the lighter.
In the safety device disclosed in U.S. Pat. No. 4,832,596, the lock member is moved to a release position along a linear path, but automatically returns to the initial position unless it is held at a lock position with a finger other than the one used for actuating the ignition mechanism. Thus, the lock member cannot steadily be released. This adversely affects the ease of releasing the lock mechanism in a gas lighter, which is generally operated with a single finger, e.g. the thumb, and, as with the preceding examples, leads to different operational results depending on the users.
To overcome such drawbacks, an auto-return safety device has been put forward in which the lock member is moved along a linear path to a release position, thereby facilitating the release of the lock mechanism, and at the same time, the lock mechanism can be held in the release position with the finger used for actuating the ignition mechanism, thus not requiring the use of another finger. However, the safety device also has drawbacks in its practical use. Specifically, in the safety device disclosed in U.S. Pat. No. 4,904,180, the lock member is incorporated in the actuation lever which is actuated to ignite the lighter, and the actuation lever can be operated with the use of the same finger that has been used in releasing the lock member, i.e., the thumb that is generally used in ignition operation, thus facilitating a releasing operation. However, when the actuation lever is actuated with the same finger (usually the thumb) which previously moved to the lock member to the release position, the lock member may inadvertently be released from the thumb and may return to the lock position. Accordingly, also in this safety device, the lock member cannot be steadily released. This adversely affects the ease of releasing the lock mechanism in the gas lighter, which is generally operated with a single finger, e.g. the thumb, and, as with the preceding examples, this leads to different operation results depending on the users.
Thus, any one of the existing child resistant safety devices has drawbacks in practical use, and hence there is still a demand for a gas lighter with a safety device which is improved in both safety and operability.
To meet this demand, a gas lighter with the following means has already been put forward. Specifically, as disclosed in U.S. Pat. No. 5,240,408, a safety device is put forward in which a resilient leaf is formed on upper part of a lighter main body, and the end of this resilient leaf engages with a part of a pressing means to prevent the depression of the pressing means, thereby effecting ignition lock. This safety device is also provided with a slide member that is vertically movable along the resilient leaf. The lighter is released from its locked state by elevating the slide member and rendering the resilient leaf deformed, so that the slide member is disengaged from the pressing means. This makes the depression of the pressing member possible, that is, ignition is possible. Together with the pressing means, the slide member is lowered to the lock position, and automatically returns to the ignition lock position when the pressing means is elevated after ignition.